This invention is related to our corresponding U.S. patent application Ser. No. 135,412 for a "Self-Contained Swab Unit" filed on the same day as this application.
In the classical taking of bacteria samples, a sterile absorbent swab or a tissue scraping blade is used to pick up bacteria by contact with the infected tissue. The swab or scraper is then placed in a culture medium to maintain the bacteria for future testing and examination.
In order to collect an accurate bacteria sampling, care must be taken to prevent the introduction of ambient bacteria from a source other than the tissue under investigation. Thus, the swab must be maintained in a sterile environment until it is applied to the infected tissue and must be immediately returned to a sterile environment thereafter while it is being transported to the culture medium.
In response to inherent difficulties in maintaining this overall sterile environment, the modern trend has favored self-contained units wherein the swab and culture medium are both carried in a sealed disposable tube. Just prior to tissue sampling, the seal is broken and the swab removed for use.
Immediately after tissue sampling, the swab is replaced in the unit and the unit is resealed. An internal seal holding the swab and culture medium separate in storage is ruptured or otherwise displaced, allowing the medium to contact the bacteria bearing swab, thus beginning the culture process.
The advantages of the modern method are readily apparent. The self-contained unit carries its own sterile environment, eliminating the previous necessity of maintaining a large scale sterile environment in the storage facility for the swabs and culture medium and during incubation. Thus, the unit can be carried and stored in a doctor's bag or in a technician's portable kit until it is needed, and once used will maintain the integrity of the sample in a sterile environment while being transported to the lab.